.\" -*- nroff -*-
.\" Copyright 2013 Los Alamos National Security, LLC. All rights reserved.
.\" Copyright 2010 Cisco Systems, Inc.  All rights reserved.
.\" Copyright 2006-2008 Sun Microsystems, Inc.
.\" Copyright (c) 1996 Thinking Machines Corporation
.\" Copyright (c) 2020      Google, LLC. All rights reserved.
.\" $COPYRIGHT$
.TH MPI_Graph_map 3 "#OMPI_DATE#" "#PACKAGE_VERSION#" "#PACKAGE_NAME#"
.SH NAME
\fBMPI_Graph_map \fP \- Maps process to graph topology information.

.SH SYNTAX
.ft R
.SH C Syntax
.nf
#include <mpi.h>
int MPI_Graph_map(MPI_Comm \fIcomm\fP, int\fI nnodes\fP, const int\fI index\fP[],
	const int\fI edges\fP[], int\fI *newrank\fP)

.fi
.SH Fortran Syntax
.nf
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_GRAPH_MAP(\fICOMM, NNODES, INDEX, EDGES, NEWRANK, IERROR\fP)
	INTEGER	\fICOMM, NNODES, INDEX(*), EDGES(*), NEWRANK, IERROR\fP

.fi
.SH Fortran 2008 Syntax
.nf
USE mpi_f08
MPI_Graph_map(\fIcomm\fP, \fInnodes\fP, \fIindex\fP, \fIedges\fP, \fInewrank\fP, \fIierror\fP)
	TYPE(MPI_Comm), INTENT(IN) :: \fIcomm\fP
	INTEGER, INTENT(IN) :: \fInnodes\fP, \fIindex(nnodes)\fP, \fIedges(*)\fP
	INTEGER, INTENT(OUT) :: \fInewrank\fP
	INTEGER, OPTIONAL, INTENT(OUT) :: \fIierror\fP

.fi
.SH INPUT PARAMETERS
.ft R
.TP 1i
comm
Input communicator (handle).
.TP 1i
nnodes
Number of graph nodes (integer).
.TP 1i
index
Integer array specifying the graph structure, see  MPI_Graph_ create.
.TP 1i
edges
Integer array specifying the graph structure.

.SH OUTPUT PARAMETERS
.ft R
.TP 1i
newrank
Reordered rank of the calling process; MPI_UNDEFINED if the calling process does not belong to graph (integer).
.ft R
.TP 1i
IERROR
Fortran only: Error status (integer).

.SH DESCRIPTION
.ft R
MPI_Cart_map and MPI_Graph_map can be used to implement all other topology
functions. In general they will not be called by the user directly, unless he or she is creating additional virtual topology capability other than that provided by MPI.

.SH ERRORS
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument.
.sp
Before the error value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

.SH SEE ALSO
.sp
MPI_Cart_map

